The present invention relates to attractants and bait stations comprising date-derived syrup products (defined herein as being made of and/or derived from dates, date paste, and/or date syrup contained therein) for attracting flies (particularly biting flies, fruit flies, filth flies, and houseflies) and methods therein.
Biting flies (including mosquitoes, sand flies, stable flies, and biting midges) are known for their blood-feeding behavior, which makes them vectors of pathogens. However, while female biting flies predominantly need blood for egg production, and sugar as their main source of energy, male biting flies (apart from Stomoxys) do not feed on blood, and are completely dependent on sugar (Killick-Kendrick, 1999; Foster, 1995, see full reference in Literature section).
Therefore, the requirement for sugar-feeding influences longevity, fecundity, dispersal, host-seeking behavior, and ultimately blood-feeding that facilitates disease transmission (Foster, 1995; Dye, 1987; Gibb et al., 1988; Müller & Schlein, 2004). According to the literature, biting flies obtain sugar meals from flowers and honeydew excreted by aphids and coccids, fruit, and to a smaller extent from green plant tissue of leaves and stems (MacVicker et al., 1990; Wallbanks et al., 1991; Schlein & Müller, 1995).
Biting flies do not find sugar sources randomly; they rather search for sugar sources actively by following olfactory cues (Foster, 1995; Müller et al., 2010; Schlein & Müller, 2010). Some observations indicate that biting flies are selective and visit different flowers and fruit according to an order of preference (Müller & Schlein, 2006; Schlein & Müller, 2008). Despite the obvious importance, there is only anecdotal information on specific sugar-meal sources, and little is known about preferences of sugar sources in the field (Foster, 1995).
This dependence on sugar of biting flies was only recently exploited for control measurements. In recent times, attractive, toxic, sugar baits were developed to attract and kill biting flies in the field. These baits basically include an attractive component, sugar as a feeding stimulant, and an oral toxin. Currently, bait stations are one of the most interesting and promising insect control techniques.
In such prior-art studies, in the absence of a suitable attractant, a non-attracting, toxic sugar solution was initially sprayed on flowering plants. Mosquitoes were attracted by the scent of the flowers, and fed on the sugar solution, consequently resulting in death. While effective in controlling mosquitoes, this method required bait application to be dependent on locating suitable flowering plants. Furthermore, the impact on “non-target” flower-visiting insects such as bees and other pollinators was very high.
In subsequent studies, extracts of numerous attractive flowers and fruits were used to attract blood-sucking Diptera to the toxic sugar bait. Candidates of flowering plants and fruit were screened for their attracting properties to biting flies. Attractants for control experiments were made from identified attractive fruits including guava, plum, honeydew melon, cactus fruit, and carob seedpods. Though the performance of such attractants was initially satisfactory, it was determined that flies were only attracted to such fruit if very ripe or even over-ripe fruit (prior to the onset of rot) was used.
Fermenting the fruit with wine or beer for a few days mitigated this limitation. The resulting attractants proved to be highly effective for the control of flies; however, the same attractants exhibited poor long-term stability in field studies, as well as poor shelf life for a commercializable product. Furthermore, the availability of over-ripe fruit in industrial quantities with a persistent quality, and the standardization of the fermentation process posed additional problems. In addition, fermented fruit and their extracted products attracted not only biting flies, but also non-target insects in some areas such as non-biting Diptera, Hymenoptera, and Lepidoptera.
Furthermore, since typical prior-art bait is a viscous substance or aqueous-gel mixture, a major drawback of prior-art bait technologies is the sensitivity to outdoor environments, such as sunlight, dust, rain, dew, and cold flow due to gravity. Cold flow of bait causes loss of material and uneven distribution along the dimensions of the bait. Baits having no outer, protective film tend to accumulate dust that sticks to the bait, while the sunlight's radiation (particularly in the UV range) can cause severe degradation over a period of time of outdoor exposure.
It would be desirable to have attractants and bait stations comprising date-derived syrup products for attracting flies. Such attractants and methods would, inter alia, overcome the limitations mentioned above.